The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Typical network management and administration solutions focus on improving network availability. Using such a network management and administration solution, a service provider may monitor service availability of its network in real-time or near real time and perform control actions on the network to enhance the service availability when any service outage has been detected. Thus, if a direct network link between New York and Tokyo is relatively congested, but if a network link between New York and London, and a network link between London and Tokyo have ample unused capacity, the service provider may re-route some traffic between New York and Tokyo to an alternate route between New York and Tokyo by way of London. Clearly, the more such alternative routes are used, even though the network availability may be maintained, the less optimal the service may be (for example, large packet losses, long delays and unpredictable jitters may be associated with the alternative routes) and the more costly the network is to be maintained. Congestion in the original link (New York, Tokyo) and the delays in the alternative links (New York, London, Tokyo) represent degradation in the overall network health, although there is no significant impact to availability.
Thus, similar to a car that may not be in an optimal condition even if it is able to run between point A and point B, a network is not necessarily a healthy network even if it still carries traffic. Just as a car without outward symptoms may fail over time, a network without proactive monitoring may develop various problems over time.